1. Field of the Invention
The present invention relates generally to mechanical devices useful to strengthen circuit boards and, more specifically, to a circuit board stiffener that can be applied utilizing Surface Mount Technology (SMT).
2. Description of the Related Art
Printed circuit boards (PCBs) are well known in the art. PCBs are typically very thin and made of layers of glass fabrics or fibers that are bonded together by resins. The thinness of a PCB provides an advantage in that the PCB does not consume much space. But, one drawback is that, due to its thinness, the PCB is rather flimsy and not structurally stable. The thinness of the PCB can make the board and it's connected circuit components vulnerable to shock and vibration. Such shock and vibration can lead to damage or breakage in service or during the mating of the PCB assembly (PCBA) with other PCBAs, other parts of the final assembly, or during the end-use of the product. Furthermore, conventional soldering processes used during the PCBA manufacturing process provide a source of heat that can soften or warp the PCB, which can cause the soldering to be uneven.
Various devices exist and are currently used in industry to provide stiffness and structural strength to PCBs. Many of these stiffeners are made of either plastic, stamped steel, or cast metals in one form or another. Typically, the stiffeners are mounted or attached to the PCB using conventional mechanical fasteners, such as screws and rivets, via a labor-intensive, manual process. In some instances, the stiffeners are soldered to the PCB, but, again, using a labor-intensive, manual process.
One drawback of the labor-intensive processes used to manually attach the stiffener to the PCB is the additional cost and time introduced to the PCBA manufacturing process. Another drawback is the inherent quality problems associated with the manual process. For example, using screws to attach the stiffener to the PCB  introduces problems associated with maintaining proper screw torque. Excessive torque can damage the PCB while inadequate torque can cause shaking and loss of retention. Using rivets typically involve the use of a suitable riveting machine. These riveting machines typically require manual setup and loading, which can add additional time and, hence, expense to the manufacturing process. Even using these riveting machines, one still is faced with the problem of insuring that the rivet is not too tight or too loose.
What is desired is an automatic process for attaching a stiffener to a PCB without introducing substantial cost and expense to existing PCBA manufacturing processes. Furthermore, a stiffener suitable for being automatically attached to a PCB using machinery typically used in a PCBA manufacturing process is also desired.